Treatment of hydrocarbon oils



glue lit) ratented Mar. 16,1937

UNITED STATES PATENT' OFFICE 2,073,973 TREATMENT OF HYDROCARBON OILS Anthony M. ckenfussy'Melrose, Fla., assignor to E. I. du Pont de Nemours & Company, Wilmington, Del., a corporation of Delaware Claims. (Cl. 196-35) This invention relates to the hydrogenation of organic compounds and catalysts therefore.

More particularly, it concerns the preparation and use of new organo-metallic compositions as 5 catalysts in hydrogenating organic compounds.

This application is a division of my application, Serial Number, 573,514 filed November 6, 1931, now Patent 2,021,567, granted Nov. 19, 1935.

Various inorganic catalysts for the hydrogenation of organic compounds have been known. Examples of such catalysts are platinum, nickel, nickel oxide, palladium, electrolytic iron, alkali metals and alkali metal hydrides. Such catalysts are either expensive or diflicult to prepare and their catalytic activity decreases, or may be entirely destroyed, during use. They often have the disadvantage of carrying the hydrogenation farther than that desired.

An object of this invention is the preparation of new compositions from an alkali metal and a hydrocarbon, especially an aromatic hydrocarbon, and the use of such compositions as catalysts in the hydrogenation of organic compounds, especially hydrogenation of aromatic hydrocarbons. A further object is a process of continuously hydrogenating hydrocarbons without the necessity of replacing or renewing the catalyst. Another object of this invention is the preparation and use of hydrogenation catalysts which are not poisoned, as by the presence of sulphur compounds. A further object is to prepare catalysts whose activity and stability increase during use and which can be used at temperatures relatively lower than is possible with other hydrogenation catalysts, such as alkali metal or alkali metal hydride. Another object of this invention is the preparation of an inexpensive catalyst, small amounts of which may be used in the hydrogenation of large quantities of aromatic 4o hydrocarbons.

The above objects are accomplished by this invention through the preparation of, and use as catalysts, of the compositions resulting from the action of an alkali metal upon a hydrocarbon,

especially an aromatic hydrocarbon having more than one benzene nucleus in the molecule, at temperatures high enough and for a period of time long enough to cause the formation of complex organo-metallic compositions. The hydrocarbon reacted with alkali metal may be in either its simple form or in its polymeric condensed 5 form, since the action of alkali metal on the simple hydrocarbons causes formation of polymers. These, however, are then able to react to form my complex organo-metallic compositions,

providing the action of alkali metal is continued long enough, and at the necessary temperatures. For convenience, these complex organo-metallic compositions I have designated herein as hydrocarbides, although I do not desire to be restricted to any theory as to composition which might be inferred from this name. The hydrocarbides of this invention are not the simple organo-metallic compounds produced at the ordinary room temperature or at comparatively lovs temperatures by the reaction of an alkali meta upon an aromatic hydrocarbon, since the hydrooarbides of my invention, although they may bl made from the same starting materials, an formed under difierent conditions and generall: at higher temperatures than these simple com pounds, and possess difierent properties, chiefi: in that they are hydrogenation catalysts, where as the corresponding simple organo-metalli compounds are not.

The invention may be illustrated by the follow ing examples:

Examplel 500 gms. of high-grade naphthalene boiling a 216-218" c. and '14 gms. of sodium metal wer heated in a steel bomb at 255-273 C. for 19 hour under a hydrogen pressure of about 280 lbs./s( in. At the end of this time, the reaction mixtur was filtered. 87.5% of the original naphthalen was recovered as tetrahydronaphthalene (tetra lin) boiling at 204-206" C. by distillation from th filtrate. 10.2% was obtained as a higher boilin polymer of naphthalene. About gms. of soli product having a black appearance was oi tained as a residue of the filtration step; th residue is the catalyst of my invention.

About 22 grams of this solid product, or hydr carbide, was mixed with 123 gms. of naphthaler and the mixture heated and agitated in the hon at 260 C. for about 12 hours, at a hydrogen pre, sure of 400-450 lbs/sq. in. At the end of th time the liquid portion, upon separation from tl hydrocarbide and distillation, gave 87% of tl original naphthalene as tetrahydronaphthalel (tetralin) boiling at 204-206 C.

To show that the solid hydrocarbide was tl catalyst, exactly the same conditions as describl above for 123 gms. of naphthalene, were used an attempt to hydrogenate a further 123 gn of naphthalene, but in the presence of sodiu instead of hydrocarbide. However, no tetral was obtained, instead a polymer of naphthale having a boiling point higher than either nap thalene or tetralin was formed. Furthermo:

no'tetralin was obtained when an attempt was made to hydrogenate naphthalene in the presence of this polymer only and under otherwise the same conditions.

The following examination shows that my catalyst contains sodium directly linked to a carbon atom, as in organo-metallic compounds. A portion of the catalyst was subjected to the action of carbon dioxide under 900 lbs/sq. in. pressure at 85 C. for 15 hours in a steel bomb while agitating in a shaking apparatus. The product of the reaction with CO2 was then treated with water and filtered. When the filtrate was treated with dilute mineral'acid, an organic acid was precipitated. The precipitate dissolved in NazCOs solution as well as in NaOH solution, which is a test for organic acid as distinguished from phenols and the like.

Small samples of hydrocarbide catalyst, prepared as described above, were withdrawn from the autoclave between successive hydrogenations of naphthalene. The reactivity of these samples toward air and water was determined as follows. After the first hydrogenation, in which the catalyst was prepared, the sample of the catalyst ignited spontaneously in the air and on water, indicating the presence of sodium hydride. After the second hydrogenation, the catalyst would ignite only on water. After the third hydrogenation hydrogen was evolved rapidly when water was added, while from the fourth hydrogenation on, hydrogen was evolved only very slowly, a tarry oil (indicating complex hydrocarbide) being formed from the reaction of the originally finely divided hydrocarbide with water. The activity of the catalyst had not decreased in the least during the disappearance of the sodium hydride.

The following example illustrates the improvement in the activity and efficiency of the catalyst during a continuous process ofv successive hydrogenation.

Example II 128 gms. of pure naphthalene, boiling at 216- 218 C. and 48.3 gms. of sodium were heated for 8 hours at 260-215 C. under a hydrogen pressure of 300 lbs/sq. in. The liquid products were distilled from the hydrocarbides under a vacuum to give the catalyst, which was used in the following successive hydrogenations, during which the liquid product of hydrogenation was distilled off in a vacuum and then more fresh naphthalene added for the next hydrogenation:

rg gg 2 3 gi'gfliif ggfiig 152E255 yieffi lbs/sq. in. (grams) tetralin The percentage yield of hydrogenated product I increased with each hydrogenation from 66.6%

Example III 178 gms. of anthracene, having a melting point of 204-208 C. and 5.3 gms. of metallic sodium were heated to 120-145 C. for 12 hours under a hydrogen pressure of 500 lbs/sq. in. The liquid products were distilled from the solid hydrocarbide and gave a yield of 48.7% of hexa-hydroanthracene boiling at 298-307" C. and 40.9% of tetra-hydro-anthracene boiling at 307-322 C. 10.1% of the liquid was obtained as a polymer of anthracene boiling above 322 C.

Example IV A mixture of 497 gms. acenaphthene boiling at 277 C. and 5 gms. of metallic sodium was heated at 300-450 C. for 11 hours under a hydrogen pressure of 400-455 lbs/sq. in. The products were separated as in Example III. The liquid portion consisted almost entirely of tetraand deca-hydro-acenaphthenes, while the solid product was chiefly hydrocarbide with some free carbon giving the material a black appearance.

Example V Lubricat- Sligh oxi- Temp., Hydrogen Duration, g o' dation gg C. assure hours added number (in grams) of product The Sligh oxidation number of a sample of this same oil heated to 260-310 C. for 5 hours under a hydrogen pressure of 450 lbs/sq. in. and in the absence of hydrocarbide was practically unchanged.

The above examples have been given merely by way of illustration of the invention and I do not wish to be limited to the exact procedure or specific materials given therein, since the catalysts may be prepared by the use of other hydrocarbons, and other alkali metals than sodium, and the hydrocarbide catalysts obtained will vary in composition accordingly. Broadly, the invention comprises the reaction of an alkali metal with a hydrocarbon at a temperature sufficiently high and for a long enough period of time to form complex organo-metallic compositions, and the use of these complex compositions as catalysts in a continuous or discontinuous process for the hydrogenation of organic compounds. The invention also includes the complex organo-metallic compositions as new compositions of matter.

My new catalysts may be used for the hydrogenation of a variety of organic compounds in addition to those given in the examples. However, they are especially applicable for use in the hydrogenation of the hydrocarbon from which they were derived.

Although the use of sodium and sodium hydride as catalysts for the hyrogenation of hydrocarbons has previously been described, the prior methods do not show the conditions necessary to form my new catalysts. Furthermore, a process of hydrogenation of organic compounds, using complex organo-metallic compositions as catalysts was previously unknown. Moreover, it was not known to use such catalysts in a continuous process, and in which the efficiency of the catalyst improves with use without becoming poisoned by impurities such as sulfur compounds.

For the purpose of brevity, I have used the term hydrocarbide in this specification and in the appended claims to designate a complex alkali metal derivative of a hydrocarbon polymer made by reacting alkali metal with a hydrocarbon at an elevated temperature, which reacts with carbon dioxide to form the-alkalinated salt of an organic acid and which also catalyzes the hydrogenation of unsaturated organic compounds.

I claim:

1. Process comprising treating a hyrocarbon oil containing unsaturated hydrocarbons with hydrogen in the presence of an alkali metal hydrocarbide.

2. Process comprising treating a lubricating oil containing unsaturated hydrocarbons with hydrogen in the presence of an alkali metal hydrocarbide, separating the hydrogenated prod-1 uct from the hydrocarbide, adding fresh quantities of said oil and continuing the process.

3. The process comprising heating a hydrocarbon oil under pressure of hydrogen with sodium to form a hydrocarbon polymer and thereafter continuing the heating until substantia amounts of a sodium hydrccarbide are formed separating the hydrocarbide from the reactioi mixture and heating a fresh quantity of hydro carbon oil with the separated hydrocarbide.

4. The process comprising heating a hydro carbon oil under pressure of hydrogen with so dium to form a hydrocarbon polymer and there after continuing the heating until substantia amounts of a sodium hydrocarbide are formed separating the hydrocarbide from the reactioi mixture and using the separated hydrocarbide a a catalyst in the hydrogenation of hydrocarboi oil.

5. The process comprising heating a hydrocar bon oil at a temperature above 250 C. under pres sure of hydrogen with sodium to form a hydro carbonpolymer and thereafter continuing th heating until substantial amounts of a sodium hy drocarbide are formed, separating the hydro carbide from the reaction mixture and heating fresh quantity of hydrocarbon oil with the sepa rated hydrocarbide.

ANTHONY M. nocxnnguss.

) L Certificate of Correction Patent No. 2,073,973. March 16, 1937.

ANTHONY M. MUCKENFUSS It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 2, first column, line 47, for 260-215 read 260315; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Oflice.

Signed and sealed this 27th day of April, A. D. 1937.

[SEAL] LESLIE FRAZER, Acting Commissioner of Patents. 

